qwt_plot_axis.cpp

Go to the documentation of this file.

/* -*- mode: C++ ; c-file-style: "stroustrup" -*- *****************************
 * Qwt Widget Library
 * Copyright (C) 1997   Josef Wilgen
 * Copyright (C) 2002   Uwe Rathmann
 *
 * This library is free software; you can redistribute it and/or
 * modify it under the terms of the Qwt License, Version 1.0
 *****************************************************************************/

#include "qwt_plot.h"
#include "qwt_math.h"
#include "qwt_scale_widget.h"
#include "qwt_scale_div.h"
#include "qwt_scale_engine.h"

class QwtPlot::AxisData
{
public:
    bool isEnabled;
    bool doAutoScale;

    double minValue;
    double maxValue;
    double stepSize;

    int maxMajor;
    int maxMinor;

    bool isValid;

    QwtScaleDiv scaleDiv;
    QwtScaleEngine *scaleEngine;
    QwtScaleWidget *scaleWidget;
};

void QwtPlot::initAxesData()
{
    int axisId;

    for ( axisId = 0; axisId < axisCnt; axisId++ )
        d_axisData[axisId] = new AxisData;

    d_axisData[yLeft]->scaleWidget =
        new QwtScaleWidget( QwtScaleDraw::LeftScale, this );
    d_axisData[yRight]->scaleWidget =
        new QwtScaleWidget( QwtScaleDraw::RightScale, this );
    d_axisData[xTop]->scaleWidget =
        new QwtScaleWidget( QwtScaleDraw::TopScale, this );
    d_axisData[xBottom]->scaleWidget =
        new QwtScaleWidget( QwtScaleDraw::BottomScale, this );

    d_axisData[yLeft]->scaleWidget->setObjectName( "QwtPlotAxisYLeft" );
    d_axisData[yRight]->scaleWidget->setObjectName( "QwtPlotAxisYRight" );
    d_axisData[xTop]->scaleWidget->setObjectName( "QwtPlotAxisXTop" );
    d_axisData[xBottom]->scaleWidget->setObjectName( "QwtPlotAxisXBottom" );

#if 1
    // better find the font sizes from the application font
    QFont fscl( fontInfo().family(), 10 );
    QFont fttl( fontInfo().family(), 12, QFont::Bold );
#endif

    for ( axisId = 0; axisId < axisCnt; axisId++ )
    {
        AxisData &d = *d_axisData[axisId];

        d.scaleEngine = new QwtLinearScaleEngine;

        d.scaleWidget->setTransformation( 
            d.scaleEngine->transformation() );

        d.scaleWidget->setFont( fscl );
        d.scaleWidget->setMargin( 2 );

        QwtText text = d.scaleWidget->title();
        text.setFont( fttl );
        d.scaleWidget->setTitle( text );

        d.doAutoScale = true;

        d.minValue = 0.0;
        d.maxValue = 1000.0;
        d.stepSize = 0.0;

        d.maxMinor = 5;
        d.maxMajor = 8;


        d.isValid = false;
    }

    d_axisData[yLeft]->isEnabled = true;
    d_axisData[yRight]->isEnabled = false;
    d_axisData[xBottom]->isEnabled = true;
    d_axisData[xTop]->isEnabled = false;
}

void QwtPlot::deleteAxesData()
{
    for ( int axisId = 0; axisId < axisCnt; axisId++ )
    {
        delete d_axisData[axisId]->scaleEngine;
        delete d_axisData[axisId];
        d_axisData[axisId] = NULL;
    }
}

const QwtScaleWidget *QwtPlot::axisWidget( int axisId ) const
{
    if ( axisValid( axisId ) )
        return d_axisData[axisId]->scaleWidget;

    return NULL;
}

QwtScaleWidget *QwtPlot::axisWidget( int axisId )
{
    if ( axisValid( axisId ) )
        return d_axisData[axisId]->scaleWidget;

    return NULL;
}

void QwtPlot::setAxisScaleEngine( int axisId, QwtScaleEngine *scaleEngine )
{
    if ( axisValid( axisId ) && scaleEngine != NULL )
    {
        AxisData &d = *d_axisData[axisId];

        delete d.scaleEngine;
        d.scaleEngine = scaleEngine;

        d_axisData[axisId]->scaleWidget->setTransformation( 
            scaleEngine->transformation() );

        d.isValid = false;

        autoRefresh();
    }
}

QwtScaleEngine *QwtPlot::axisScaleEngine( int axisId )
{
    if ( axisValid( axisId ) )
        return d_axisData[axisId]->scaleEngine;
    else
        return NULL;
}

const QwtScaleEngine *QwtPlot::axisScaleEngine( int axisId ) const
{
    if ( axisValid( axisId ) )
        return d_axisData[axisId]->scaleEngine;
    else
        return NULL;
}
bool QwtPlot::axisAutoScale( int axisId ) const
{
    if ( axisValid( axisId ) )
        return d_axisData[axisId]->doAutoScale;
    else
        return false;
}

bool QwtPlot::axisEnabled( int axisId ) const
{
    if ( axisValid( axisId ) )
        return d_axisData[axisId]->isEnabled;
    else
        return false;
}

QFont QwtPlot::axisFont( int axisId ) const
{
    if ( axisValid( axisId ) )
        return axisWidget( axisId )->font();
    else
        return QFont();

}

int QwtPlot::axisMaxMajor( int axisId ) const
{
    if ( axisValid( axisId ) )
        return d_axisData[axisId]->maxMajor;
    else
        return 0;
}

int QwtPlot::axisMaxMinor( int axisId ) const
{
    if ( axisValid( axisId ) )
        return d_axisData[axisId]->maxMinor;
    else
        return 0;
}

const QwtScaleDiv &QwtPlot::axisScaleDiv( int axisId ) const
{
    return d_axisData[axisId]->scaleDiv;
}

const QwtScaleDraw *QwtPlot::axisScaleDraw( int axisId ) const
{
    if ( !axisValid( axisId ) )
        return NULL;

    return axisWidget( axisId )->scaleDraw();
}

QwtScaleDraw *QwtPlot::axisScaleDraw( int axisId )
{
    if ( !axisValid( axisId ) )
        return NULL;

    return axisWidget( axisId )->scaleDraw();
}

double QwtPlot::axisStepSize( int axisId ) const
{
    if ( !axisValid( axisId ) )
        return 0;

    return d_axisData[axisId]->stepSize;
}

QwtInterval QwtPlot::axisInterval( int axisId ) const
{
    if ( !axisValid( axisId ) )
        return QwtInterval();

    return d_axisData[axisId]->scaleDiv.interval();
}

QwtText QwtPlot::axisTitle( int axisId ) const
{
    if ( axisValid( axisId ) )
        return axisWidget( axisId )->title();
    else
        return QwtText();
}

void QwtPlot::enableAxis( int axisId, bool tf )
{
    if ( axisValid( axisId ) && tf != d_axisData[axisId]->isEnabled )
    {
        d_axisData[axisId]->isEnabled = tf;
        updateLayout();
    }
}

double QwtPlot::invTransform( int axisId, int pos ) const
{
    if ( axisValid( axisId ) )
        return( canvasMap( axisId ).invTransform( pos ) );
    else
        return 0.0;
}


double QwtPlot::transform( int axisId, double value ) const
{
    if ( axisValid( axisId ) )
        return( canvasMap( axisId ).transform( value ) );
    else
        return 0.0;
}

void QwtPlot::setAxisFont( int axisId, const QFont &font )
{
    if ( axisValid( axisId ) )
        axisWidget( axisId )->setFont( font );
}

void QwtPlot::setAxisAutoScale( int axisId, bool on )
{
    if ( axisValid( axisId ) && ( d_axisData[axisId]->doAutoScale != on ) )
    {
        d_axisData[axisId]->doAutoScale = on;
        autoRefresh();
    }
}

void QwtPlot::setAxisScale( int axisId, double min, double max, double stepSize )
{
    if ( axisValid( axisId ) )
    {
        AxisData &d = *d_axisData[axisId];

        d.doAutoScale = false;
        d.isValid = false;

        d.minValue = min;
        d.maxValue = max;
        d.stepSize = stepSize;

        autoRefresh();
    }
}

void QwtPlot::setAxisScaleDiv( int axisId, const QwtScaleDiv &scaleDiv )
{
    if ( axisValid( axisId ) )
    {
        AxisData &d = *d_axisData[axisId];

        d.doAutoScale = false;
        d.scaleDiv = scaleDiv;
        d.isValid = true;

        autoRefresh();
    }
}

void QwtPlot::setAxisScaleDraw( int axisId, QwtScaleDraw *scaleDraw )
{
    if ( axisValid( axisId ) )
    {
        axisWidget( axisId )->setScaleDraw( scaleDraw );
        autoRefresh();
    }
}

void QwtPlot::setAxisLabelAlignment( int axisId, Qt::Alignment alignment )
{
    if ( axisValid( axisId ) )
        axisWidget( axisId )->setLabelAlignment( alignment );
}

void QwtPlot::setAxisLabelRotation( int axisId, double rotation )
{
    if ( axisValid( axisId ) )
        axisWidget( axisId )->setLabelRotation( rotation );
}

void QwtPlot::setAxisMaxMinor( int axisId, int maxMinor )
{
    if ( axisValid( axisId ) )
    {
        maxMinor = qBound( 0, maxMinor, 100 );

        AxisData &d = *d_axisData[axisId];
        if ( maxMinor != d.maxMinor )
        {
            d.maxMinor = maxMinor;
            d.isValid = false;
            autoRefresh();
        }
    }
}

void QwtPlot::setAxisMaxMajor( int axisId, int maxMajor )
{
    if ( axisValid( axisId ) )
    {
        maxMajor = qBound( 1, maxMajor, 10000 );

        AxisData &d = *d_axisData[axisId];
        if ( maxMajor != d.maxMajor )
        {
            d.maxMajor = maxMajor;
            d.isValid = false;
            autoRefresh();
        }
    }
}

void QwtPlot::setAxisTitle( int axisId, const QString &title )
{
    if ( axisValid( axisId ) )
        axisWidget( axisId )->setTitle( title );
}

void QwtPlot::setAxisTitle( int axisId, const QwtText &title )
{
    if ( axisValid( axisId ) )
        axisWidget( axisId )->setTitle( title );
}

void QwtPlot::updateAxes()
{
    // Find bounding interval of the item data
    // for all axes, where autoscaling is enabled

    QwtInterval intv[axisCnt];

    const QwtPlotItemList& itmList = itemList();

    QwtPlotItemIterator it;
    for ( it = itmList.begin(); it != itmList.end(); ++it )
    {
        const QwtPlotItem *item = *it;

        if ( !item->testItemAttribute( QwtPlotItem::AutoScale ) )
            continue;

        if ( !item->isVisible() )
            continue;

        if ( axisAutoScale( item->xAxis() ) || axisAutoScale( item->yAxis() ) )
        {
            const QRectF rect = item->boundingRect();

            if ( rect.width() >= 0.0 )
                intv[item->xAxis()] |= QwtInterval( rect.left(), rect.right() );

            if ( rect.height() >= 0.0 )
                intv[item->yAxis()] |= QwtInterval( rect.top(), rect.bottom() );
        }
    }

    // Adjust scales

    for ( int axisId = 0; axisId < axisCnt; axisId++ )
    {
        AxisData &d = *d_axisData[axisId];

        double minValue = d.minValue;
        double maxValue = d.maxValue;
        double stepSize = d.stepSize;

        if ( d.doAutoScale && intv[axisId].isValid() )
        {
            d.isValid = false;

            minValue = intv[axisId].minValue();
            maxValue = intv[axisId].maxValue();

            d.scaleEngine->autoScale( d.maxMajor,
                minValue, maxValue, stepSize );
        }
        if ( !d.isValid )
        {
            d.scaleDiv = d.scaleEngine->divideScale(
                minValue, maxValue,
                d.maxMajor, d.maxMinor, stepSize );
            d.isValid = true;
        }

        QwtScaleWidget *scaleWidget = axisWidget( axisId );
        scaleWidget->setScaleDiv( d.scaleDiv );

        int startDist, endDist;
        scaleWidget->getBorderDistHint( startDist, endDist );
        scaleWidget->setBorderDist( startDist, endDist );
    }

    for ( it = itmList.begin(); it != itmList.end(); ++it )
    {
        QwtPlotItem *item = *it;
        if ( item->testItemInterest( QwtPlotItem::ScaleInterest ) )
        {
            item->updateScaleDiv( axisScaleDiv( item->xAxis() ),
                axisScaleDiv( item->yAxis() ) );
        }
    }
}